During the Maya early Anthropocene (2000 BCE - 1000 CE) in Mesoamerica, socio-environmental interactions contributed to the rise and decline of the ancient Maya civilization. At the scale of the exploitation territories of the Maya cities, the temporal variations of hydrological and sedimentary dynamics in response to anthropogenic and climate drivers are still poorly known.

This manuscript analyses and presents a regional comparison of the dynamics of one of the most transformed hydrosystems and morpho-sedimentary systems by the societies of the Southern Maya Lowlands, during the second half of the Holocene. It focuses on the lake basin of the polje named El Infierno bajo and its watershed, which was the main water storage area for the Maya city of Naachtun —a large regional capital between 150 and 950 CE —, and which contains many remains of hydraulic and agrarian structures. This integrated palaeolimnological, geoarchaeological and hydrological approach, based on the analyses of morpho-sedimentary archives, LiDAR altimetry data, hydrological and geochemical data, resulted in the construction of hydro-sedimentary baselines (pre- syn- and post-ancient Maya anthropogenic impacts).

During the past 5500 years, hydrosedimentary fluctuations were marked by the alternation of seven main hydrological periods, characterized by high and low lake levels (alternately perennial, intermittent and dry lake) and six main erosion and sediment transfer periods, marked by strong and low alluvial and colluvial detrital inputs in the lowlands. Anthropogenic and climate forcings have independently or jointly controlled the hydrologic and sedimentary budgets of the lake basin. Lithofacies, depositional processes, accumulation rates and drivers of the anthropogenic detrital inputs — the so-called “Maya clays” —, are analyzed and quantified from ~1500 BCE to ~1150 CE. It thus reveals one of the longest periods of occupation and exploitation of natural resources, for over 2500 years during the Preclassic, Classic and Postclassic Maya periods. The hydro-sedimentary dynamics in the bajos of the Elevated Interior Region, such as El Infierno, enabled the long-term exploitation of water and soil resources for agrarian purposes, thanks to the construction of hydraulic and agrarian palimpsest landscapes shaped by the socio-ecosystems.

Référence : Cyril Castanet, Louise Purdue, Marc Testé, Aline Garnier, Anne-Lise Develle-Vincent, Fatima Mokadem, Christine Hatté, Caroline Gauthier, Philippe Lanos, Philippe Dufresne, Eva Lemonnier, Lydie Dussol, Julien Hiquet, Philippe Nondédé. Multi-millennial human impacts and climate change during the Maya early Anthropocene: implications on hydro-sedimentary dynamics and socio-environmental trajectories (Naachtun, Guatemala). Quaternary Sciences Reviews (2022) 283, 107458 - doi: 10.1016/j.quascirev.2022.107458